What is one reason that northerners lost interest in reconstruction? a. the united states was about to go to war with mexico. b. northerners were focused on the political corruption plaguing the nation. c. northerners never really wanted to bring the south back into the union. d. northerners felt the job was done.

Northerners lost interest in Reconstruction was because "B. Northerners were focused on the political corruption plaguing the nation," since this was during the Progressive Era. The Progressive Era was a period of widespread social activism and political reform across the US, from the 1890s to the 1920s. The main objectives was to eliminate problems caused by industrialization, urbanization, immigration, and corruption in government.